LAKEPORT -- Lake County Sheriff Frank Rivero took the stand briefly Wednesday morning during a pretrial hearing in the nearly two-year-old case of an alleged gang fight at Konocti Vista Casino.

Three Sonoma County men are set to face a jury in May for charges stemming from the June 4, 2011 incident.

Authorities allege Timothy R. Bianchi, Nicolas F. Carrillo and Josh L. Johnson -- along with a fourth man who is still at large -- acted as members of the Hells Angels Motorcycle Club when they fought with a known member of the Vagos Motorcycle Club at the Lakeport casino.

Bianchi, 35, Carrillo, 34, and Johnson, 37, pleaded not guilty to the charges against them.

The trio appeared at the Lake County Courthouse Wednesday for a hearing on pending motions in the case. Each man has his own defense counsel.

Among the issues debated Wednesday was the question of whether Rivero is a material witness, someone with significant information about a criminal case that could affect its outcome.

Deputy district attorney Art Grothe argued Rivero was not a material witness and said he would not call the sheriff to the stand during the trial.

Clough said the fact the sheriff testified during the March 2012 preliminary hearing "clearly suggested Mr. Rivero was a material witness."

Rivero testified for about a half-hour Wednesday, telling the court about his involvement in the investigation, which he said included obtaining copies of casino surveillance footage.

Recently retired Judge David W. Herrick heard Rivero's testimony but did not make a ruling on the issue Wednesday.

The pending Lake County District Attorney's Office investigation into the sheriff could have a bearing on the Hells Angels case.

DA Don Anderson is investigating whether Rivero was untruthful during the inquiry into a 2008 incident in which Rivero, a deputy at the time, fired a shot at a suspect who reportedly brandished a weapon. The man was uninjured.

The incident was investigated at the time and no charges were filed against Rivero, who said he told the truth during the original inquiry.

Anderson contended if Rivero were untruthful, that information would have to be shared with parties in prosecutions in which Rivero could be a witness, under the case of Brady v. Maryland. Such details could be used to impeach an officer's testimony.

The DA said the investigation is done but he is not ready to release his findings publicly.

Should Rivero take the stand at the Hells Angels trial, the outcome of the DA's inquiry might result in information the defense could use to impeach the sheriff's testimony.

Anderson also appeared in the courtroom Wednesday, having been subpoenaed by the defense, but he did not take the stand.

Clough criticized the DA's pending Brady process during the hearing, saying, "I've never seen it happen in any other county."

The defendants have also filed a motion asking for access to details Rivero's personnel records.

The judge read the briefs and other documents related to the Rivero issues Wednesday morning but said he thought the matters might take longer to flesh out than originally anticipated.

As a result, the parties set aside those issues and took up other pending motions.

The judge granted a motion to quash a defense subpoena requesting certain records from the Western States Information Network, a federally funded resource for law enforcement.

The attorneys then began to talk about issues related to the prosecution's gang expert, Jorge Gil-Blanco.

A key issue in the case is whether the Sonoma County chapter of the Hells Angels is a criminal street gang.

The defense subpoenaed Gil-Blanco asking for materials in his possession that he relied on to render his opinion about the Hells Angels.

Grothe argues the defense requests go beyond the scope of what can be asked for under the law.

As the afternoon hours ran thin, the parties determined it unlikely that Gil-Blanco could take the stand and complete his testimony Wednesday.

Because Gil-Blanco was unavailable Thursday, the judge rescheduled his testimony and further arguments on evidence related to his involvement in the case for March 22.

The court is set to address the remainder of the motions Thursday morning at the Lake County Courthouse.

Jeremy Walsh is a staff reporter for Lake County Publishing. Reach him at 263-5636, ext. 37 or jwalsh@record-bee.com. Follow him on Twitter, @JeremyDWalsh.